RHCE Study Guide for RHEL5 v1.1
• Look at the latest objectives for the exam.
• Remember the commands required.
• If you don't understand a section, take that as a
clue that you need further study.
• Practice, practice, practice!
Boot Single
boot into single user mode
• at grub screen, "a", "space", "1", enter
Network Configuration
• system-config-network
Files
• /etc/sysconfig/network-scripts/ifcfg-eth0
• /etc/sysconfig/network
Hostname Resolution
• /etc/resolv.conf
• /etc/hosts
X Window System
• /etc/X11/xinit/xinitrc.d
• /etc/X11/xorg.conf
• /etc/inittab
• system-config-display
• /tmp and /home have enough space
• Ctrl-Alt-F1 to F8
• Ctrl-Alt-Backspace
Hard Disk Commands
• fdisk /dev/hda
• partprobe
• mdadm -C /dev/md0 -l 5 -n 3 /dev/hda6
/dev/hda7 /dev/hda8
• mke2fs -j /dev/md0
• e2label /dev/hda2 /data
• mount -t ext3 /dev/hda7 /data7
Configure Printing
• system-config-printer
• /etc/cups/cupsd.conf
• lpadmin
• lpstat, lpq
• reject disable
• accept /usr/bin/enable
Cron and at Jobs
• copy script to /etc/cron.daily, /etc.cron.monthly
• Modify /etc/crontab: crontab -e
• List cron jobs: crontab -l
• Add an at job: at [-f file] TIME
• View at queue: atq
• Remove at jog: atrm job
Install NIS or LDAP
• Install ypbind, portmap
• system-config-authentication
• check: Enable NIS Support, or Enable LDAP
Support
• click: Configure NIS..., or Configure LDAP...
• configure firewall, if required
Test NIS or LDAP
• ypwhich
• nisdomainname -y
• genent services
• getent passwd smith
• rpcinfo -p
NIS or LDAP Files
• /etc/yp.conf
• /etc/sysconfig/network
• /etc/pam.d/system-auth
• /etc/nsswitch.conf
Configure autofs
• /etc/auto.master
◦ /home/guests /etc/auto.guests
--
timeout=60
• /etc/auto.guests
◦ *
-rw,soft,intr
server1:/home/guests/&
• service autofs restart
• chkconfig portmap on
• chkconfig autofs on
Manage Users, and Groups
• groupadd -g 1000 groupname
• useradd username
• usermod -G groupname username
◦ (-G for primary group)
Manage Quotas
• quotacheck -cuf /home
• quotaon /home
• edquota username
• quota username
• repquota /home
Filesystem Permissions
• mkdir -p /depts/finance
• chgrp sales /depts/finance
• chmod 770 /depts/*
• chmod g+s /depts/*
• chown sam /depts/managers
• ls -l /depts/
Install and Update rpms
• rpm -ivh filenamex.i386.rpm
• rpm -Uvh filenamex.i386.rpm
• Verify an RPM:
◦ rpm --import /usr/share/rhn/RPM-GPG-KEY
◦ rpm -K /tmp/rpmversion.i386.rpm
Install from yum Repository
• /etc/yum.conf
• /etc/yum.repos.d/
System Bootloader
/boot/grub/grub.conf
• # root (hd0,0)
• # kernel /vmlinuz-version ro
root=/dev/vg00/lv00 crashkernel=128M@16M
• # initrd /initrd-version.img
Implement Software RAID
• partprobe
• mdadm -C /dev/md0 -l 5 -n 3 /dev/hda6
/dev/hda7 /dev/hda8
• mke2fs -j /dev/md0
• /etc/fstab
• mdadm --detail /dev/md0
• fail, recover, add:
◦ mdadm /dev/md0 -a /dev/sda1
Set Kernel Run-time Parameters
• vi /etc/sysctl.conf
• xxx.xx.xxx=1
• sysctl -p
• sysctl -a | grep xxx
Diagnose and Correct Boot Failures
• /etc/rc.d/rc.sysinit
• /etc/rc.d/rc adn /etc/rc.d/rc?.d
• /etc/rc.d/rc.local
• /boot/grub/grub.conf
• filesystem
• /etc/fstab
• fsck /dev/hda
Create a Logical Volume
• First create physical volume, then volume
group, then logical volume PV -> VG -> LV
• pvcreate /dev/hda6 /dev/hda7 /dev/hda8
• vgcreate vg0 /dev/hda6 /dev/hda7
• lvcreate -L 500M -n data0 vg0
• ext2online /dev/vg0/data0
• SELinux
• getenforce
• setenforce 1
• check context with ls -Z
• chcon -R --reference /var/www/html
/var/www/html/wwwnew
Configure HTTP
• install httpd
• modify /etc/httpd/conf/httpd.conf file
• service httpd restart
• chkconfig httpd on
• service httpd configtest
Configure Samba Share
• Install samba
• vi /etc/samba/smb.conf
• configure firewall
NFS
• Modify /etc/exports
• start nfs & portmap
• verify config, & check mounts
• exportfs -v
• showmount -e localhost
• rpcinfo -p localhost
• service nfs reload
Automount
• mkdir /net
• vi /etc/auto.master
• start services -- portmap, autofs
FTP
• install vsftpd
• create incoming directory
• mkdir -p /var/ftp/incoming
• vi /etc/vsftpd/vsftpd.conf
• start vsftpd
• service vsftpd start
Web proxy
• Install squid, and start the service
•
vi /etc/squid
• service squid reload
• Configure browser to test
SMTP
• Install sendmail, sendmail-cf, sendmail-doc
• modify /etc/mail/sendmail.mc
• m4 sendmail.mc > sendmail.cf (or make)
• service sendmail restart
IMAP, IMAPS, and POP3
• install dovecot
• vi /etc/dovcot.conf
• protocols = xxx
• service dovecot restart
• chkconfig dovecot on
SSH
• /etc/ssh/
• ~/.ssh/
DNS
Install bind, bind-utils, and caching-nameserver
• vi /etc/named.conf
To verify:
•
named-checkconf
•
named-checkzone example.com
example.com.zone
• Check /etc/resolv.conf on client machines
NTP
• /etc/ntp.conf
• ntpstat
• service ntpd restart
Firewall
• /etc/sysconfig/iptables
• iptables -L
• iptables -F
• service iptables save
• service iptables restart
• chkconfig iptables on
PAM
• /lib/security/
• /etc/pam.d/
Configure Service
• Install RPM
• rpm -ivh servicename.rpm
• Modify Configuration and Firewall
• Start Service
• service servicename restart
• Set Service to Start on Reboot
• chkconfig servicename on
